package com.wmx.string;

import javax.print.attribute.HashAttributeSet;
import java.util.*;

public class StringTest {
    public static void main(String[] args) {
       /* String str = "wumengxin";

        Long start = new Date().getTime();
        for (int i = 0 ;i<=100000;i++){
            str+=i;
        }
        Long end = new Date().getTime();
        System.out.println("结果=============="+str);
        System.out.println("运行时间========"+(end-start)/1000);


        System.out.println("===========StringBuffer================");*/
    /*    StringBuffer strB = new StringBuffer("wumengxin");

        Long start1 = new Date().getTime();
        for (int i = 0 ;i<=100000;i++){
            strB.append(i);
        }
        Long end1 = new Date().getTime();
        System.out.println("结果=============="+strB.toString());
        System.out.println("运行时间========"+(end1-start1)/1000);*/

        Map map = new HashMap();

        map.put(null, "wumengxin");

        System.out.println(map.get(null));

        LinkedHashMap linkedHashMap = new LinkedHashMap();

        Set set = new HashSet();


    }
}
